Clinical significance of KL-6 in immune-checkpoint inhibitor treatment for non-small cell lung cancer

PURPOSE

Krebs von den Lungen-6 (KL-6) functions as a tumor marker, as well as a diagnostic tool for interstitial pneumonia (IP). However, the significance of KL-6 in the immune-checkpoint inhibitor (ICI) treatment of non-small cell lung cancer (NSCLC), especially in patients without IP, is unknown.

METHODS

This multicenter, retrospective study, which included patients with advanced NSCLC who received ICI therapy, analyzed the association between serum KL-6 values and ICI efficacy and the association between serum KL-6 values and ICI-induced interstitial lung disease (ILD) occurrence, focusing primarily on patients without IP.

RESULTS

In total, 322 patients had available KL-6 values before ICI therapy. Among 202 patients without IP who received ICI monotherapy, the high-KL-6 group (≥ 500 U/mL) showed significantly shorter progression-free survival (PFS) and overall survival (OS) than the low-KL-6 group (< 500 U/mL) (median: 2.1 vs. 3.6 months, p = 0.048; median: 9.2 vs. 14.5 months, p = 0.035). There was no significant difference in response rate between the KL-6 high and low groups (19% vs. 29%, p = 0.14). In the multivariate analysis, high KL-6 was a significant predictor of poor PFS (hazard ratio [HR], 1.52; 95% confidence interval [CI] 1.10-2.11, p = 0.012) and OS (HR, 1.51; 95% CI 1.07 - 2.13, p = 0.019) for patients treated with ICI monotherapy. There was no significant difference in the occurrence rate of ILD between the high KL-6 and low KL-6 groups in patients with (20% vs. 15%, p = 1.00) or without IP (12% vs. 12%, p = 1.00).

CONCLUSION

In ICI monotherapy for NSCLC without IP, elevated serum KL-6 levels were associated with poorer outcomes.

RBM17 Expression Is Associated With the Efficacy of ICI Monotherapy in NSCLC With Low PD-L1 Expression

BACKGROUND/AIM

Immune checkpoint inhibitors (ICIs) are currently a standard treatment tool for non-small cell lung cancer (NSCLC). RNA-binding motif protein 17 (RBM17), a splicing factor, is frequently over-expressed in NSCLC, but little is known about the role of RBM17 in the efficacy of ICIs for NSCLC. Thus, we investigated the correlation between RBM17 expression and ICI efficacy in NSCLC.

PATIENTS AND METHODS

Biopsy or surgical specimens were collected from patients with advanced or recurrent NSCLC who received ICI monotherapy or chemo-immunotherapy in a first-line setting. RBM17 expression was examined using immunohistochemistry. The correlation between the efficacy of ICI monotherapy or chemo-immunotherapy and RBM17 expression was evaluated.

RESULTS

Among the 218 cases, 115 (52.8%) cases were positive for RBM17 expression. RBM17 expression was not associated with the objective response rate (ORR) or progression-free survival (PFS) in either of the ICI monotherapy or chemo-immunotherapy groups. However, among those with a low PD-L1 expression level (PD-L1 <50%; n=86), RBM17 expression was significantly associated with a better ORR (p=0.045) and a better PFS (p<0.001) in the ICI monotherapy group, and was significantly associated with a poor ORR in the chemo-immunotherapy group (p=0.041).

CONCLUSION

RBM17 might be a useful predictive marker for a higher efficacy of ICI monotherapy in NSCLC patients with a low PD-L1 expression level.

Influence of Smoking History on the Effectiveness of Immune-checkpoint Inhibitor Therapy for Non-small Cell Lung Cancer: Analysis of Real-world Data

BACKGROUND/AIM

There is no real-world data in an Asian population to investigate the difference between the outcome of immune-checkpoint inhibitor (ICI) monotherapy and combination therapy for non-small cell lung cancer (NSCLC) based on smoking status. In this study, we investigated the correlation between smoking status and the efficacy of ICI therapy for NSCLC patients.

PATIENTS AND METHODS

This multicentre retrospective study enrolled patients with recurrent or metastatic NSCLC who were treated using ICI therapy between December 2015 and July 2020. We analysed the objective response rate (ORR) of patients who received ICI monotherapy or combination therapy, based on smoking status using Fisher's exact test, and progression-free survival (PFS) and overall survival (OS) based on smoking status using the Kaplan-Meier method, the log-rank test, and Cox proportional hazards model.

RESULTS

A total of 487 patients were included in the study. In the ICI monotherapy group, non-smokers showed significantly lower ORR and shorter PFS and OS than smokers (10% vs. 26%, p=0.002; median: 1.8 vs. 3.8 months, p<0.001; median: 8.0 vs. 15.4 months, p=0.026). In the ICI combination therapy group, non-smokers showed significantly longer OS than smokers (median: not reached vs. 26.3 months, p=0.045), and there was no significant difference in ORR and PFS between non-smokers and smokers (63% vs. 51%, p=0.43; median: 10.2 vs. 9.2 months, p=0.81). In the multivariate analysis of patients who received ICI combination therapy, the "non-smoker" status was not significantly associated with PFS [hazard ratio (HR)=1.31; 95% confidence interval (CI)=0.70-2.45, p=0.40] and OS (HR=0.40; 95% CI=0.14-1.13, p=0.083).

CONCLUSION

Non-smokers showed worse outcomes than smokers with ICI monotherapy, but not with ICI combination therapy.

Vimentin expression correlates with immune-checkpoint inhibitor efficacy in non-small cell lung cancer

BACKGROUND

Although vimentin is often expressed in non-small cell lung cancer (NSCLC), the association between vimentin expression and immune-checkpoint inhibitor (ICI) efficacy remains unclear.

METHODS

This retrospective multicenter study enrolled patients with NSCLC who received ICI treatment between December 2015 and July 2020. The authors constructed tissue microarrays and performed immunohistochemical staining with vimentin. They analyzed the relationship between vimentin expression rate and objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

Immunohistochemically evaluable specimens on microarray blocks were available for 397 patients, of whom 343 (86%) were negative (<10%), 30 (8%) were positive (10%-49%), and 24 (6%) were highly positive (≥50%) for vimentin expression. Both rates of programmed death-ligand 1 (PD-L1) tumor proportion score ≥1% and ≥50% were significantly higher in the vimentin-positive group (≥10%) than the vimentin-negative group (<10%) (96% vs. 78%, p = .004; 64% vs. 42%, p = .006, respectively). In patients treated with ICI monotherapy, ORR, PFS, and OS were significantly better in the vimentin-positive group (10%-49%) than in the vimentin-negative group (<10%) (54% vs. 25%, p = .003, median = 7.9 vs. 3.2 months, p = .011; median = 27.0 vs. 13.6 months, p = .015, respectively), whereas there was no significant difference in PFS and OS between the vimentin highly positive group (≥50%) and the vimentin-negative group (<10%) (median = 3.4 vs. 3.2 months, p = .57; median = 7.2 vs. 13.6 months, p = .086, respectively).

CONCLUSIONS

Vimentin expression correlated with PD-L1 expression and ICI efficacy.

PLAIN LANGUAGE SUMMARY

We constructed tissue microarrays and performed immunohistochemical staining with vimentin on 397 patients with advanced non-small cell lung cancer who were treated with immune-checkpoint inhibitor (ICI). The vimentin-positive group who were treated with ICI monotherapy showed significantly better objective response rate, progression-free survival, and overall survival than the vimentin negative group. The measurement of vimentin expression will aid in determining appropriate immunotherapy strategies.

SP142 evaluation contributes to the prediction of immune checkpoint inhibitor efficacy in non-small cell lung cancer with high PD-L1 expression assessed by 22C3

Background

It remains unclear whether assessing programmed death-ligand 1 (PD-L1) expression by SP142 plus 22C3 adds value for predicting the response to immunotherapy in non-small cell lung cancer (NSCLC).

Methods

This retrospective multicenter study included patients with advanced NSCLC treated with immune-checkpoint inhibitors. We constructed tissue microarrays (TMAs) and performed immunohistochemical staining with 22C3 and SP142 assays. We denoted the PD-L1 tumor proportion score (TPS) obtained from clinical medical records based on 22C3 staining as "22C3 (C)" and that obtained with 22C3 staining using our TMA as "22C3 (TMA)". SP142 staining was evaluated in both tumor cells and immune cells. We assessed the concordance between each PD-L1 assessment method and analyzed the objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) based on the PD-L1 expression level determined using the 22C3 and SP142 assays.

Results

In total, 288 patients were included. Among those with 22C3 (TMA) ≥50%, 60% of patients showed SP142 TC3 or IC3; among patients with 22C3 (C) <1%, 9% and 18% exhibited 22C3 (TMA) ≥1% and SP142 TC1/2/3 or IC1/2/3, respectively. Among patients with 22C3 (C) ≥50% treated with immune-checkpoint inhibitor monotherapy, the SP142 TC1/2/3 or IC1/2/3 group showed significantly better ORR, PFS and OS than the SP142 TC0 and IC0 group (54% vs. 29%, P=0.040, median =11.0 vs. 3.2 months, P=0.002, median =27.9 vs. 12.6 months, P=0.030, respectively). Multivariate analysis revealed that SP142 TC0 and IC0 was an independent unfavorable prognostic factor for PFS and OS in patients with 22C3 (C) ≥50% treated with immune-checkpoint inhibitor monotherapy. For those with 22C3 (C) ≥50% and SP142 TC0 and IC0, immune-checkpoint inhibitor concurrent with chemotherapy tended to result in a longer PFS and OS than immune-checkpoint inhibitor monotherapy (median =13.7 vs. 2.3 months, P=0.054, median = not estimable vs. 12.0 months, P=0.064, respectively).

Conclusions

SP142 evaluation contributes to the prediction of immune-checkpoint inhibitor efficacy in NSCLC with high PD-L1 expression assessed by 22C3.

Time course and localization of nerve growth factor expression and sensory nerve growth during progression of knee osteoarthritis in rats

OBJECTIVES

Nerve growth factor (NGF) and sensory nerves are key factors in established osteoarthritis (OA) knee pain. We investigated the time course of NGF expression and sensory nerve growth across early and late stages of OA progression in rat knees.

DESIGN

Knee OA was induced by medial meniscectomy in rats. OA histopathology, NGF expression, and calcitonin gene-related peptide immunoreactive (CGRP-IR) nerves were quantified pre-surgery and post-surgery at weeks 1, 2, 4 and 6. Pain-related behavior was evaluated using dynamic weight distribution and mechanical sensitivity of the hind paw.

RESULTS

NGF expression in chondrocytes increased from week 1 and remained elevated until the advanced stage. In synovium, NGF expression increased only in early stages, whereas in osteochondral channels and bone marrow, NGF expression increased in the later stages of OA progression. CGRP-IR nerve density in suprapatellar pouch peaked at week 4 and decreased at week 6, whereas in osteochondral channels and bone marrow, CGRP-IR innervation increased through week 6. Percent ipsilateral weight-bearing decreased throughout the OA time course, whereas reduced paw withdrawal thresholds were observed only in later stages.

CONCLUSION

During progression of knee OA, time-dependent alterations of NGF expression and CGRP-IR sensory innervation are knee tissue specific. NGF expression increased in early stages and decreased in advanced stage in the synovium but continued to increase in osteochondral channels and bone marrow. Increases in CGRP- IR sensory innervation followed increases in NGF expression, implicating that NGF is a key driver of articular nerve growth associated with OA pain.

Association of thyroid transcription factor-1 with the efficacy of immune-checkpoint inhibitors in patients with advanced lung adenocarcinoma

Background

We aimed to identify the relationship between thyroid transcription factor‐1 (TTF‐1) expression of lung adenocarcinoma and the efficacy of immune‐checkpoint inhibitor (ICI) therapy.

Methods

This retrospective multicenter study comprised patients with advanced lung adenocarcinoma treated with ICI monotherapy. We collected clinical medical records including data on TTF‐1 expression and analyzed the relationship between TTF‐1 expression and programmed death‐ligand 1 tumor proportion score (PD‐L1 TPS), objective response rate (ORR), progression‐free survival (PFS), and overall survival (OS).

Results

In total, 108 patients with lung adenocarcinoma were analyzed. The rate of TPS ≥1% and ≥50% in patients with positive TTF‐1 expression was significantly higher than that in patients with negative TTF‐1 expression (88% vs. 60%, p < 0.001; 65% vs. 24%, p < 0.001). The ORR was significantly higher in TTF‐1 positive patients than in TTF‐1‐negative patients (38% vs. 8%, p = 0.003). Among patients with TPS ≥50% and 1%–49%, the ORR in TTF‐1 positive and negative patients was 48% (26/54) versus 17% (1/6) (p = 0.21), and 32% (6/19) versus 11% (1/9) (p = 0.37), respectively. The ORR for patients with TPS <1% was 0% in both the TTF‐1 negative and positive cases. The median PFS and OS was significantly longer in TTF‐1‐positive patients than in TTF‐1‐negative patients (5.4 vs. 1.6 months, p < 0.001; 18.2 vs. 8.0 months, p = 0.041). Multivariate analysis revealed that TTF‐1‐negative status was an independent unfavorable prognostic factor for PFS.

Conclusion

Patients with TTF‐1‐positive status receiving ICI monotherapy showed better outcomes than those with TTF‐1‐negative lung adenocarcinoma.

Vascular endothelial growth factor receptor 2 expression and immunotherapy efficacy in non-small cell lung cancer

It is unclear whether tumor vascular endothelial growth factor receptor 2 expression affects the therapeutic efficacy of immune‐checkpoint inhibitors and antiangiogenic agents. This retrospective, multicenter study included patients with advanced non–small cell lung cancer who were treated with immune‐checkpoint inhibitors. We constructed tissue microarrays and performed immunohistochemistry with an anti‐vascular endothelial growth factor receptor 2 antibody. We analyzed immune and tumor cell staining separately in order to determine their correlation with the objective response rate, progression‐free survival, and overall survival in patients receiving immune‐checkpoint inhibitors. Of 364 patients, 37 (10%) expressed vascular endothelial growth factor receptor 2 in immune cells and 165 (45%) in tumor cells. The objective response rate, progression‐free survival, and overall survival were significantly worse in patients treated with immune checkpoint inhibitor monotherapy who expressed vascular endothelial growth factor receptor 2 in immune cells than those who did not (10% vs 30%, p = 0.028; median = 2.2 vs 3.6 months, p = 0.012; median = 7.9 vs 17.0 months, p = 0.049, respectively), while there was no significant difference based on tumor cell expression (24% vs 30%, p = 0.33; median = 3.1 vs 3.5 months, p = 0.55; median = 13.6 vs 16.8 months, p = 0.31). There was no significant difference in overall survival between patients treated with and without antiangiogenic agents in any treatment period based on vascular endothelial growth factor receptor 2 expression. Immune checkpoint inhibitor efficacy was limited in patients expressing vascular endothelial growth factor receptor 2 in immune cells.

A case of PD-L1 negative advanced pulmonary sarcomatoid carcinoma effectively treated with atezolizumab, carboplatin, paclitaxel, and bevacizumab

Pulmonary sarcomatoid carcinoma (PSC) is an extremely rare neoplasm with poor prognosis and no established treatment. A 50-year-old man presented with fever, was found to have a mass measuring 14 cm in the right upper lobe of the chest, along with right pleural effusion on computed tomography (CT). Positron emission tomography-CT revealed abnormal tracer uptake in the area corresponding to the mass in the upper lobe. Hence, convex-probe endobronchial ultrasound-guided transbronchial needle aspiration was performed. Histological examination revealed dense proliferation of spindle tumor cells and no programmed death-ligand 1 (PD-L1) expression. Thus, he was diagnosed with PSC (cT4N0M1a, clinical stage IVA), and four-agent combination chemotherapy with atezolizumab, carboplatin, paclitaxel, and bevacizumab was initiated. Marked shrinkage of the mass and symptomatic improvements were observed following the treatment initiation. Tumor shrinkage was further noted after shifting to maintenance therapy with atezolizumab and bevacizumab; the patient exhibited no symptom exacerbation 2 years later and continued the treatment. Our case showed that four-agent combination chemotherapy with atezolizumab, carboplatin, paclitaxel, and bevacizumab could be an effective treatment option for advanced PSC with or without PD-L1 expression.

Phase 1b study of ramucirumab in combination with erlotinib or osimertinib for untreated EGFR-mutated non-small cell lung cancer patients with asymptomatic brain metastases

OBJECTIVES

The study was designed to investigate the safety of ramucirumab administered in combination with erlotinib or osimertinib for patients with untreated EGFR-mutated non-small cell lung cancer (NSCLC) and asymptomatic brain metastases, a patient subgroup in which these regimens have remained untested.

MATERIALS AND METHODS

This phase 1b study (RELAY-Brain) consisted of two cohorts with three patients each. Patients with asymptomatic brain metastases received ramucirumab every 2 weeks plus either daily oral erlotinib or osimertinib until disease progression or intolerable toxicity. The primary objective was to assess dose-limiting toxicity (DLT), defined as central nervous system (CNS) hemorrhage of grade ≥ 2.

RESULTS

Six patients were enrolled. Neither DLT nor serious or unexpected adverse events were observed. One treatment-related adverse event of grade ≥ 3 (hypertension of grade 3) was apparent. Common adverse events were generally manageable. The median number of ramucirumab administrations was 18.5 (range, 13 to 31), and there were no detected episodes of CNS hemorrhage. Five of the six patients showed an objective systemic response. Although only one patient had a measurable CNS lesion at baseline, a confirmed intracranial partial response was observed.

CONCLUSION

Ramucirumab in combination with erlotinib or osimertinib showed safety for EGFR-mutated NSCLC with brain metastases.

Tumor microenvironment disparity in multiple primary lung cancers: Impact of non-intrinsic factors, histological subtypes, and genetic aberrations

•

Tumor microenvironment (TME) was compared among multiple primary lung cancers (MPLCs).

•

Sex and smoking status concomitantly impacted PD-L1 expression in paired tumors.

•

EGFR mutations were independently associated with PD-L1 expression.

•

KRAS mutations altered the TMEs according to the types of co-mutations.

•

The number of FOXP3-positive t cells reflected histological subtypes.

Introduction

Multiple primary lung cancers (MPLCs) occur in common carcinogenetic risks such as lifestyle, biological aging, immune responses, hormones, and metabolism. Although MPLCs harbor various genetic profiles within the same individuals, differences in the tumor microenvironment (TME) are unclear. We investigated the impact of genetic aberrations, non-intrinsic factors, and pathological subtypes on tumor immunity.

Materials and Methods

In total, 73 surgically resected specimens from 32 patients with MPLC were analyzed. PD-L1 expression in tumor cells (TCs) and immune cells (ICs), CD3-positive tumor-infiltrating lymphocytes (TILs), CD8/CD3 ratios, and FOXP3-positive TILs that compose TMEs were evaluated by immunohistochemistry and classified on a score of 0–2. 38 tumors were sequenced for somatic mutations in 409 cancer-associated genes.

Results

Females and never or light smokers had a higher incidence of PD-L1-negative tumors and a higher concordance rate. PD-L1 positivity in TCs and ICs was significantly less frequent in EGFR-mutated than in wild-type tumors. Differences in the score of TMEs were observed between the KRAS-mutated-only tumor and the KRAS and TP53-co-mutated tumors, and between the KRAS-mutated-only tumor and the KRAS and STK11-co-mutated tumors. Significantly more FOXP3-high TILs were observed in invasive pathological subtypes than in non-invasive ones.

Conclusion

Comparing TMEs among MPLCs revealed that non-smokers or light smokers and females were unlikely to express PD-L1 regardless of tumor site and confirmed that the EGFR mutations and co-occurring KRAS and STK11 or TP53 mutations were associated with TME. Pathological subtypes may impact the efficacy of immune therapy due to their potential correlations with regulatory T cells.

Mutational landscape of multiple primary lung cancers and its correlation with non-intrinsic risk factors

Multiple primary lung cancers (MPLCs) harbour various genetic profiles among the tumours, even from individuals with same non-intrinsic risk factors. Paired mutational analyses were performed to obtain a census of mutational events in MPLC and assess their relationship with non-intrinsic risk factors. Thirty-eight surgical specimens from 17 patients diagnosed as MPLC were used. Extracted DNAs were sequenced for somatic mutations in 409 cancer-associated genes from a comprehensive cancer panel. We statistically analysed the correlation between each driver mutation frequency and non-intrinsic risk factors using Fisher's exact test, and whether genetic mutations occurred concomitantly or randomly in MPLC using an exact test. Comprehensive genetic analyses suggested different mutation profiles in tumours within the same individuals, with some exceptions. EGFR, KRAS, TP53, or PARP1 mutations were concomitantly detected in some MPLC cases. EGFR mutations were significantly more frequent in never or light smokers and females. Concomitant EGFR or KRAS mutations in MPLCs were significantly more frequent than expected by chance (P = .0023 and .0049, respectively) suggesting a more prominent role of non-intrinsic risk factors in EGFR and KRAS mutations than other mutations, which occurred more randomly. Concomitant EGFR or KRAS mutations were particularly prominent in never or light smokers and males.

Can smoking duration alone replace pack-years to predict the risk of smoking-related oncogenic mutations in non-small cell lung cancer? A cross-sectional study in Japan

OBJECTIVE

To investigate whether smoking duration alone can replace pack-years to predict the risk of oncogenic mutations in non-small cell lung cancer (NSCLC).

DESIGN

A cross-sectional study using the baseline dataset from the Japan Molecular Epidemiology for Lung Cancer Study.

SETTING

Forty-three medical institutions nationwide in Japan.

PARTICIPANTS

From July 2012 to December 2013, 957 patients with newly diagnosed stage I-IIIB NSCLC who underwent surgery were enrolled, and molecular analyses were performed on 876 samples (from 441 ever-smokers and 435 never-smokers).

MAIN OUTCOMES MEASURED

We calculated the area under the receiver operating characteristic curve (AUC) values using logistic regression to compare between the predictive values of smoking duration and pack-years for mutational frequencies in the v-Ki-ras2 Kirsten rat sarcoma (KRAS), tumour suppressor p53 (TP53), and epidermal growth factor receptor (EGFR) genes and for cytosine-to-adenine base substitution (C>A).

RESULTS

For predicting KRAS mutations, the AUC values for smoking duration and pack-years were 0.746 (95% CI 0.682 to 0.800) and 0.759 (95% CI 0.700 to 0.810), respectively (p=0.058). For predicting KRAS mutations in smokers, the AUC values for smoking duration and pack-years were 0.772 (95% CI 0.697 to 0.833) and 0.787 (95% CI 0.714 to 0.845), respectively (p=0.036). There were no significant differences between the AUC values for smoking duration and pack-years in terms of predicting TP53 and EGFR mutations and C>A. Pack-years was a significantly better predictor of KRAS mutations than smoking duration.

CONCLUSION

Smoking duration was not significantly different from pack-years in predicting the likelihood of smoking-related gene mutations. Given the recall bias in obtaining smoking information, smoking duration alone should be considered for further investigation as a simpler alternative to pack-years.

Differences in molecular epidemiology of lung cancer among ethnicities (Asian vs. Caucasian)

Background

Differences in carcinogenesis and therapeutic efficacy according to ethnicity have been reported for lung cancer, and understanding differences in genetic mutation profiles among ethnicities is important for interpreting the results of clinical trials, preventing carcinogenesis, and individualizing treatment. However, no studies have focused on differences in mutation profiles among different ethnicities using large-scale genomic analysis data with detailed information on smoking history, the main cause of lung cancer.

Methods

To clarify the differences in genetic mutation profiles between Caucasian and Japanese subjects, we compared data from The Cancer Genome Atlas, which mainly included Caucasians, with results from the Japan Molecular Epidemiology for lung cancer study, which is an epidemiological study only involving Japanese subjects. We divided the participants into four groups according to smoking status and performed comparative analysis by tissue type (lung adenocarcinoma and squamous cell lung cancer).

Results

In patients with lung adenocarcinoma, the frequency of EGFR mutations was lower in Caucasian subjects than in Japanese subjects (14.6% vs. 51.1%), whereas the frequencies of mutations in other genes, namely KRAS (32.9% vs. 9.3%), TP53 (45.2% vs. 20.7%), BRAF (9.6% vs. 1.3%), PIK3CA (5.9% vs. 2.6%), KEAP1 (17.8% vs. 0.5%), NF1 (10.9% vs. 0.5%), STK11 (17.8% vs. 0.7%), RBM10 (8.7% vs. 0.1%), and MET (7.8% vs. 0.1%), were higher in Caucasian subjects. Among patients with squamous cell carcinoma, TP53 (81.2% vs. 49.1%), PIK3CA (14.5% vs. 6.8%), KEAP1 (12.7% vs. 0.9%), and NFE2L2 mutations (15.8% vs. 13.6%) were more common in Caucasian subjects.

Conclusions

Ethnicity is an important and complex characteristic that must be recognized and considered, even in the era of precision medicine. We should collaborate to share data for different ethnicities and incorporate them into clinical practice and the design of global clinical studies. Carefully designed molecular epidemiological studies focusing on ethnic differences are warranted.

The impact of estrogen receptor status on EGFR/TP53/CTNNB1 axis in the evolution of non-small cell lung cancer

e21035

Background: The role of estrogen receptor status in the carcinogenesis of lung cancer remains elusive. A census of clonal and sub-clonal mutations has been defined through the analyses of evolutionary histories of cancers. We previously reported a prospective multicenter molecular epidemiology study (JME study; Kawaguchi T, J Clin Oncol 2016), which included the expression levels of estrogen receptors β (ER) using immunohistochemistry(IHC) and the mutational profile using next generation sequencing as well as solid smoking information and reproductive/ hormonal risk factors from the detailed questionnaire. Methods: Utilizing the data of the JME study, the impact of ER in lung cancer development was explored. All the patients underwent surgery. In 441 ever- and 435 never-smokers, ER were observed in 46.4% and 53.5%, respectively. The cancer-associated 72 gene mutations and 5 gene amplifications examined in this study included EGFR, SMAD4, APC, FBXW7, BRAF, STK11, PIK3CA, TP53, PTEN, KRAS, CTNNB1, NFE2L2, NF1, and MET. ALK fusion was detected by IHC. Patients were enrolled between July 2012 and December 2013, with follow up until November 30th, 2017.Cox proportional hazards models were used to assess the ER expression on relapse free survival (RFS) and overall survival (OS). A logistic regression model was applied to assess the impact of ER (positive vs. negative) on gene alterations, using sex, smoking history, age and stage as independent variables. Results: ER expression was significantly higher in never smokers (vs. ever smokers; p = 0.022) and earlier stage (stage I vs. II-IV; p = 0.002). Patients with ER positive tumors had a longer RFS than those with negative tumors (RFS rate at 4 years: 33.7 vs. 26.5%; p = 0.021), however, there was no significant difference in OS between the two groups (p = 0.108). In the impact of ER status on the gene alterations, mutations in EGFR (p = 0.003), TP53 (p = 0.007) and CTNNB1 (p = 0.027) were significantly associated with ER expression. Multivariate analysis showed that EGFR mutations (OR = 1.394, 95%CI: 1.029-1.890, p = 0.032) and CTNNB1 mutations (OR = 0.272, 95%CI: 0.087-0.853, p = 0.026) were significantly associated with ER expression, while there was a trend for significance with TP53 mutations (OR = 0.737, 95%CI: 0.537-1.011, p = 0.059). Conclusions: ER positive status triggered the clonal EGFR mutations and suppressed the sub-clonal mutations of TP53 and CTNNB1. It is suggested that ER plays a critical role in the alterations of EGFR/TP53/ CTNNB1 axis in lung cancer evolution.

Early-onset meningitis associated with atezolizumab treatment for non-small cell lung cancer: case report and literature review

Immune checkpoint inhibitors (ICIs) have improved the overall survival of many patients with advanced cancers. However, unlike cytotoxic and targeted drugs, ICIs may cause various immune-related adverse events (irAEs). Among these irAEs, autoimmune meningitis is very rare. Here, we report a case of early-onset, atezolizumab-induced meningitis after administration of one dose of atezolizumab. A 56-year-old man with lung adenocarcinoma had received seventh-line treatment with atezolizumab when he experienced dysarthria. Blood examinations, including the measurement of electrolytes, glucose, and organ functions, were unremarkable, but enhanced head magnetic resonance imaging T1-weighted images showed meningeal enhancement. Although cerebral spinal fluid (CSF) examinations revealed elevated lymphocyte and protein levels, no cancer cells were detected in the CSF. CSF cultures and serological tests, including polymerase chain reaction for herpes simplex virus, were negative. The patient was therefore diagnosed with atezolizumab-triggered autoimmune meningitis. With steroid treatment, the patient's clinical and neurological state improved immediately and he recovered to baseline conditions. Prompt diagnosis and therapeutic intervention are essential for the effective treatment of autoimmune meningitis.

Impact of Tongue Pressure and Peak Expiratory Flow Rate on Nutritional Status of Older Residents of Nursing Homes in Japan: A Cross-Sectional Study

OBJECTIVES

Swallowing function is critical for continuing oral feeding to prevent frailty in older adults. In this study, we investigated the impact of tongue pressure and pulmonary function on the nutritional status of older adults.

DESIGN, SETTING, PARTICIPANTS

This cross-sectional study was conducted in Kitakyushu, Japan from August 2017 to November 2018. Fifty-two residents aged >65 years of age from three nursing care insurance facilities in Kitakyushu City, Japan were recruited.

MEASUREMENTS

Oral health status, swallowing function, nutritional status using a mini nutritional assessment short form (MNA-SF), cognitive function, activities of daily living, peak expiratory flow rate (PEFR) for pulmonary function, and tongue pressure were assessed. The associations between nutritional status and the above factors were analysed using a logistic regression model.

RESULTS

Participants were divided into two groups: well-nourished group (MNA-SF ≤12) and undernutrition group (MNA-SF <12). Multivariate logistic regression analysis revealed that the correlations of PEFR [odds ratio (OR) = 0.23, 95% confidence interval (CI) = 0.23-0.89 p=0.033) and tongue pressure (OR = 0.88, 95% CI = 0.88-0.99, p=0.029) remained significant even after adjustment with possible confounders.

CONCLUSION

Maximum tongue pressure and PEFR in older adults were significantly associated with their nutritional status. These findings suggest that maintaining oral and pulmonary function may be a preventive factor against a decrease in the nutritional status of older frail adults.

Impact of tumor microenvironment on the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors in patients with EGFR-mutant non-small cell lung cancer

We retrospectively investigated the impact of the tumor microenvironment (TME) on the efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) as first-line treatment in 70 patients with advanced EGFR-mutant non-small cell lung cancer and who were seen at Osaka City University Hospital (Osaka, Japan) between August 2013 and December 2017. Using immunohistochemical staining with 28-8 and D7U8C Abs, the tumor proportion score was assessed for programmed cell death-1 ligand-1 (PD-L1), as high (50% or more) or low (less than 50%), and ligand-2 (PD-L2) expression, respectively. The extent of CD8+ tumor-infiltrating lymphocytes was evaluated on a scale of 0-3, with 0-1 as low and 2-3 as high. The TME of the 52 evaluable pretreatment specimens was categorized into 4 subtypes, according to the respective PD-L1 tumor proportion and CD8+ scores, as follows: (a) high/high (13.5%, n = 7); (b) low/low (42.3%, n = 22); (c) high/low (17.3%, n = 9); and (d) low/high (26.9%, n = 14). Expression of PD-L2 was significantly the highest in type 1 (57.1% vs 4.5% vs 11.1% vs 7.1%, respectively; P = .0090). Response rate was significantly the lowest in type 1 (14.3% vs 81.8% vs 66.7% vs 78.6%, respectively; P = .0085). Progression-free survival was the shortest in type 1 and the longest in type 4 (median, 2.4 vs 11.3 vs 8.4 vs 17.5 months, respectively; P = .00000077). The efficacy of EGFR-TKIs differed according to the TME, and the phenotype with high PD-L1 and CD8+ expression might be the subset that would poorly benefit from such treatment.

Can smoking duration alone replace pack-years to predict the risk of smoking-related oncogenic mutations in non-small cell lung cancer (NSCLC)?

e20017

Background: P has widely been used for the risk assessment of lung cancer and chronic obstructive pulmonary disease (COPD). We previously reported that mutations in KRAS, TP53, and EGFR were also associated with P from a prospective multicenter molecular epidemiology study (JME study; Kawaguchi T, J Clin Oncol 2016). Recently, D alone has been reported to provide stronger risk estimates of COPD than P. Here, we show the comparison of these two indices in predicting the risk of smoking-related oncogenic mutations in NSCLC, utilizing the database from the JME study including detailed smoking information and the mutational profile by next generation sequencing. Methods: In 439 ever- and 437 never-smokers, the frequency of mutations in KRAS, TP53 and EGFR were 9.4, 26.8 and 42.5%, respectively, and smoking-related cytosine to adenine base substitution (C > A) was observed in 12.7 % of cases. AUC values (area under the ROC curves) for logistic regression determined from P and D to predict the mutations or C > A change were compared, considering gender, age, stage and histology as covariates. Results: The median of P and D were 43 (1-189) and 41 (years, 1-65) in smokers, respectively. The AUC values in EGFR and KRAS were numerically higher than others, suggesting stronger association with smoking. There was no significant difference in AUC values between P and D in TP53, EGFR and C > A, and P was a significantly better estimate of KRAS mutations (table). Conclusions: P remains the standard method to evaluate the risk of oncogenic mutations in NSCLC. D, however, warrants further investigation as a simpler alternative to P.[Table: see text]

Impact of medial versus lateral knee pain on deep tissue hyperalgesia and muscle strength

BACKGROUND

Accumulating evidence indicates that knee pain gives rise to sensory and motor alterations, however, whether different profile of knee pain causes different alterations has not been investigated. The purpose of this experimental study is to clarify characteristics of medial and lateral knee pain and its potential for modulating sensory and motor function in humans.

METHODS

Fourteen healthy men were included. Medial knee pain (MP) was induced by injection of hypertonic saline (0.5 mL) into the tibial insertion of the medial collateral ligament. For comparison, lateral knee pain (LP) was induced by injection of hypertonic saline identically into the iliotibial tract. Isotonic saline was injected contralaterally as control. Pain intensity was assessed on a continuous electronic visual analogue scale (VAS). Before, during and after the painful state, pressure pain thresholds from the knee (PPTs), maximal isometric muscle strength of the quadriceps and grip power were assessed bilaterally.

RESULTS

MP demonstrated significantly higher VAS scores than LP and compared with control. PPTs decreased on medial and lateral knee in MP but only on the lateral knee in LP. Quadriceps muscle strength and grip power reduced bilaterally in both models, however, MP caused significantly greater reduction of ipsilateral quadriceps strength compared with LP.

CONCLUSION

Medial knee pain has a greater impact on deep tissue hyperalgesia and reduction of the muscle strength compared with lateral knee pain. This is a novel finding that should be taken into consideration in a treatment strategy for painful knee patients.

SIGNIFICANCE

The experimental medial knee pain model demonstrated higher pain intensity, more localized pain distribution, widespread deep tissue hyperalgesia and more severe inhibition of muscle strength compared with the lateral knee pain model.

Endoscopic photodynamic therapy using talaporfin sodium for recurrent intranasal carcinomas after radiotherapy in three dogs

Radiation is the treatment of choice for canine nasal tumours but, in almost all cases, there is local recurrence associated with poor prognosis. This report describes the effect of endoscopic photodynamic therapy using talaporfin sodium for canine intranasal carcinoma recurring after radiation therapy. Rhinoscopic photodynamic therapy was administered after radiation therapy in three dogs with recurrent intranasal carcinoma. Two to 24 illuminations of a 665-nm diode laser were performed two hours after intravenous bolus injection of 5·0 mg/kg of talaporfin sodium. Photodynamic therapy induced almost complete remission and prolonged survival time in all cases suggesting that it might be a useful treatment for intranasal carcinomas that recur after radiation.

User-independent assessment of conditioning pain modulation by cuff pressure algometry

BACKGROUND

The use of conditioning pain modulation (CPM) is hampered by poor reproducibility and lack of user-independent paradigms. This study refined the CPM paradigm by applying user-independent cuff algometry.

METHODS

In 20 subjects, the CPM effect of conditioning with cuff stimulation on the arm was investigated by pain test stimuli on the contralateral leg before and in parallel with different cuff conditionings (10, 30, 60 kPa/60 s; 30, 60 kPa/10 s). As test stimulus, another cuff was inflated (1 kPa/s) until the subjects detected the pain tolerance threshold (PTT) during which the pain detection threshold (PDT) and the pressure at a pain intensity of 6 cm on a 10-cm visual analogue scale (PVAS6) were extracted. For comparison, pressure pain thresholds (PPTs) as test stimuli were recorded by the user-dependent handheld pressure algometry. Combinations of cuff locations for conditioning (pain intensity standardized) and contralateral test stimuli were additionally evaluated (leg-arm, leg-leg, arm-thigh). The test-retest reliability in two sessions 1 month apart was assessed in five CPM protocols.

RESULTS

In all protocols, the PDT, PVAS6 and PTT increased during conditioning compared with baseline (p < 0.05). The CPM effect (i.e. conditioning minus baseline) for PVAS6, PTT and PPT increased for increasing conditioning intensities (p < 0.05). The CPM effects were not significantly different for changes in conditioning durations or conditioning/test stimulus locations. In two sessions, the CPM effects for PVAS6 and PTT assessed after 60 s of conditioning on the leg/thigh showed the highest intra-class correlations (0.47-0.73), where they were 0.04-0.6 for PPTs.

CONCLUSIONS

The user-independent cuff algometry is reliable for CPM assessment and for supra-pain threshold test stimuli better than the user-dependent technology.

SIGNIFICANCE

A user-independent CPM technique where the conditioning is controlled by one cuff stimulation, and the test-stimulus is provided by another cuff stimulation. This study shows that cuff algometry is reliable for CPM assessment.

Mechanism of action of newly developed vitamin D analogue

26,27-F6-1,25(OH)2D3 has a higher potency both in vivo and in vitro systems, and longer duration of action in vivo, instead of almost equal binding to 1,25(OH)2D3 receptor and comparatively short serum half-life. To date, the mechanism of higher action is not known, but using these analogues as a mirror we might be able to elucidate the mechanism of action or the metabolism of the kidney hormone, 1,25(OH)2D3.

Constipation is not associated with colonic diverticula: a multicenter study in Japan

BACKGROUND

The association of diverticula with bowel habits is unclear. We therefore analyzed the association between diverticula and bowel habits in over 1000 Japanese individuals.

METHODS

Japanese subjects who underwent total colonoscopies at seven centers in Japan from June to September 2013 were analyzed. Bowel habits were evaluated using the Gastrointestinal Symptom Rating Scale, and stool form was assessed using a part of the Bristol Scale and Rome ΙΙΙ criteria. Diverticula were diagnosed by colonoscopy with a transparent soft-short hood.

KEY RESULTS

The study evaluated 1066 subjects, 648 males and 418 females (ratio, 1.55 : 1), of mean age 63.9 ± 13.0 years. After adjusting for age and sex, the presence of constipation was associated with a significantly reduced likelihood of diverticula (odds ratio [OR] = 0.70, 95% confidence interval [CI] 0.52-0.93). When assessed according to the location of diverticula, the presence of constipation was associated with a significantly decreased likelihood of left-sided (OR = 0.39, 95% CI 0.16-0.93), but not right-sided (OR = 1.10, 95% CI 0.48-2.53), diverticula. Furthermore, stool form was unrelated with the presence or absence of diverticula.

CONCLUSIONS & INFERENCES

The wide-spread hypothesis that constipation was associated with colonic diverticula was not supported. Rather, we found that the absence of diverticula was associated with constipation, suggesting the need to reassess the etiology of colonic diverticula.

Repeated intra-articular injections of acidic saline produce long-lasting joint pain and widespread hyperalgesia

BACKGROUND

Synovial fluid in inflamed joint shows a drop in pH, which activates proton-gated ion channels in nociceptors. No studies have ever tried to develop and characterize acid-induced joint pain.

METHODS

Rats were injected intra-articularly with pH 4.0 acidic saline twice, 5 days apart. Pain-related behaviour tests including weight-bearing asymmetry, paw withdrawal threshold and knee compression threshold were conducted. To clarify the roles of proton-gated ion channels, rats were injected intra-articularly with selective antagonists for ASIC1a, ASIC3 and TRPV1 on day 5 (before the second injection) or on day 14. Underlying peripheral and central pain mechanisms were evaluated using joint histology, interleukin-1β concentrations in the synovium, single-fibre recording of the knee afferent and expression of phosphorylated cyclic adenosine monophosphate-responsive element-binding protein (p-CREB) in the spinal dorsal horn.

RESULTS

Repeated injections of acidic saline induced weight-bearing asymmetry, decrease in paw withdrawal threshold and knee compression threshold bilaterally, which lasted until day 28. Early administration of ASIC3 antagonist reduced the bilateral and long-lasting hyperalgesia. Neither articular degeneration nor synovial inflammation was observed. C-fibre of the knee afferent was activated by acidic saline, which was attenuated by pre-injection of ASIC3 antagonist. p-CREB expression was transiently up-regulated bilaterally on day 6, but not on day 14.

CONCLUSION

We developed and characterized a model of acid-induced long-lasting bilateral joint pain. Peripheral ASIC3 and spinal p-CREB played important roles for the development of hyperalgesia. This animal model gives insights into the mechanisms of joint pain, which is helpful in developing better pain treatments.

Effects of Janus kinase inhibitor tofacitinib on circulating serum amyloid A and interleukin-6 during treatment for rheumatoid arthritis

The Janus kinase inhibitor tofacitinib is currently being investigated as a disease-modifying agent in rheumatoid arthritis (RA). We investigated the in-vivo effects of tofacitinib treatment for 4 weeks on elevated circulating acute-phase serum amyloid (SAA) levels in 14 Japanese patients with RA. SAA levels fell from 110·5 ± 118·5 μg/ml (mean ± standard deviation) at treatment initiation to 15·3 ± 13·3 μg/ml after 4 weeks treatment with tofacitinib. The reduction in SAA levels was greater in patients receiving tofacitinib plus methotrexate compared with those receiving tofacitinib monotherapy. Tofacitinib was also associated with reduced serum interleukin (IL)-6, but had no effect on serum levels of soluble IL-6 receptor. Patients were divided into groups with adequate (normalization) and inadequate SAA responses (without normalization). Serum IL-6 levels were reduced more in the group with adequate SAA response compared with those with inadequate SAA response. These results suggest that tofacitinib down-regulates the proinflammatory cytokine, IL-6, accompanied by reduced serum SAA levels in patients with active RA. The ability to regulate elevated serum IL-6 and SAA levels may explain the anti-inflammatory activity of tofacitinib.

Inhibition of Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway in rheumatoid synovial fibroblasts using small molecule compounds

Janus kinase (JAK) inhibitors have been developed as anti-inflammatory agents and have demonstrated clinical efficacy in rheumatoid arthritis (RA). We investigated if JAK-3-selective inhibition alone could disrupt cytokine signalling in rheumatoid synovial fibroblasts. In-vitro studies were performed using synovial fibroblasts isolated from patients with RA. Levels of activated JAK and signal transducer and activator of transcription (STAT) proteins were detected by immunoblot analysis. Target-gene expression levels were measured by reverse transcription-polymerase chain reaction (RT-PCR) or real-time PCR. The JAK inhibitors CP-690,550 and INCB028050 both suppressed activation of JAK-1/-2/-3 and downstream STAT-1/-3/-5, as well as the expression levels of target proinflammatory genes (MCP-I, SAA1/2) in oncostatin-M (OSM)-stimulated rheumatoid synovial fibroblasts. In contrast, the JAK-3-selective inhibitor, PF-956980, suppressed STAT-1/-5 activation but did not affect STAT-3 activation in OSM-stimulated rheumatoid synovial fibroblasts. In addition, PF-956980 significantly suppressed MCP-1 gene expression, but did not block SAA1/2 gene expression in OSM-stimulated rheumatoid synovial fibroblasts. These data suggest that JAK-3-selective inhibition alone is insufficient to control STAT-3-dependent signalling in rheumatoid synovial fibroblasts, and inhibition of JAKs, including JAK-1/-2, is needed to control the proinflammatory cascade in RA.

The impact of childhood abuse history, domestic violence and mental health symptoms on parenting behaviour among mothers in Japan

BACKGROUND

To assess the impact of childhood abuse history, domestic violence experiences and mental health symptoms on the parenting behaviour of mothers in Japan who have separated from violent husbands or partners.

METHODS

A self-administered questionnaire survey was conducted on a sample of mothers (n = 304) and their children (n = 498) residing in 83 mother-child homes in Japan. The survey assessed the mothers' childhood abuse history (physical, psychological and sexual abuse and neglect history), domestic violence experiences, current mental health symptoms (dissociative, depressive and traumatic symptoms) and parenting behaviours after moving into the homes to separate from a violent husband or partner.

RESULTS

The mothers' childhood abuse history and experience of domestic violence were not associated with their not playing with their children. In contrast, the mothers' dissociative and depressive symptoms were significantly associated with not playing with their children. Although there was no association between the mothers' total childhood abuse history and not praising their children, their childhood physical abuse history was significantly associated with their not praising their children. The dissociative and depressive symptoms were also associated with no praise. Interestingly, the experience of domestic violence showed an inverse association with no praise.

CONCLUSIONS

Mental health symptoms, more specifically dissociative and depressive symptoms, are associated with a decrease in parenting quality. Mothers who were physically abused as children are less likely to praise their own children, independent of maternal mental health symptoms. In contrast, mothers who experienced domestic violence but subsequently separated from their violent husbands or partners are more likely to praise their children. The treatment of mental health symptoms, particularly dissociative and depressive symptoms, therapy for childhood abuse history and separation from violent husbands or partners might be effective ways to enhance the quality of parenting in Japan.

Molecular characterization of heterochromatin proteins 1a and 1b from the silkworm, Bombyx mori

Heterochromatin protein 1s (HP1s) are nonhistone chromosomal proteins that play a direct role in the formation and maintenance of heterochromatin structure. Similarly to Caenorhabditis elegans, silkworms possess holocentric chromosomes, in which diffused kinetochores extend along the length of each chromosome. We have isolated two silkworm HP1 homologues, BmHP1a and BmHP1b. Cytological analysis showed a unique localization of BmHP1s during cell division, in which these proteins first appear to dissociate from the chromosomes, but then return to enclose the chromosomes during metaphase. BmHP1s formed homo- and hetero-dimers and interacted with BmSu(var)3-9, which is a methyltransferase for histone H3 lysine 9 (H3K9). We further showed, using a silkworm cell-based reporter system, that BmHP1b had higher transcriptional repression activity than BmHP1a, whereas BmHP1a interacted more strongly with BmSu(var)3-9 than did BmHP1b. These results suggest that silkworm HP1a and HP1b may play different roles in heterochromatin formation in holocentric silkworm chromosomes.

Successful treatment of wound breakdown caused by pyoderma gangrenosum after total knee arthroplasty

Pyoderma gangrenosum is a rare ulcerative disorder of the skin of unknown etiology. We present a case of pyoderma gangrenosum that occurred following total knee arthroplasty, which was initially misdiagnosed as severe wound infection. Repeated debridement procedures resulted in a large soft tissue defect around the anterior knee joint. The patient was treated successfully with a latissimus dorsi musculocutaneous flap under immunosuppressive therapy. Pyoderma gangrenosum is often misdiagnosed as an infected wound, but the treatment for theses differential diagnoses is completely different. When a lesion is refractory to thorough treatment for infection, a diagnosis of pyoderma gangrenosum should be considered.

Imaging features contributing to the diagnosis of ameloblastomas and keratocystic odontogenic tumours: logistic regression analysis

OBJECTIVE

The aim of this study was to clarify the characteristic imaging features that can be used to differentiate ameloblastomas from keratocystic odontogenic tumours and to examine the significant imaging features contributing to a correct diagnosis.

METHODS

60 observers (39 specialists in oral and maxillofacial radiology and 21 non-specialists) examined CT and/or panoramic images of 10 ameloblastomas and 10 keratocystic odontogenic tumours shown on a webpage and made diagnoses. Their correct answer ratios were then calculated. The imaging features of the tumours were evaluated and expressed as binary numbers or quantitative values. The imaging features that contributed to a correct diagnosis were elucidated using logistic regression analysis.

RESULTS

The mean correct answer ratio was 61.3% ± 17.2% for the diagnosis of ameloblastomas and keratocystic odontogenic tumours. CT images produced higher correct answer ratios for diagnosis of keratocystic odontogenic tumours by specialists. The significantly different imaging features between ameloblastomas and keratocystic odontogenic tumours were the degree of bone expansion and the presence of high-density areas. The significant imaging features contributing to a correct imaging diagnosis were the number of locules, the presence of high-density areas and the inclusion of impacted teeth.

CONCLUSION

The presence of high-density areas is the most useful feature in the differential diagnosis of ameloblastomas and keratocystic odontogenic tumours based on comparison of the imaging features of both tumours and examination of the diagnostic contributions of these features.

The effect of horizontal X-ray beam angulation on the detection of furcation defects of mandibular first molars in intraoral radiography

OBJECTIVES

The aim was to investigate the effect of changes in horizontal X-ray beam angulation in intraoral radiography on the detection accuracy of furcation defects in the mandibular first molar, and to examine the anatomical relationship between the roots and furcation area as a possible cause of changes in detectability.

METHODS

Simulated furcation defects with various depths were created in five mandibular first molars. Intraoral radiographs were taken at various horizontal angulations of the projection beams. The diagnostic accuracies were determined based on receiver operating characteristic analysis. The geometric relationship that might influence the accuracy was investigated through use of a compact cone beam CT in 59 first molar areas.

RESULTS

Although the horizontal angulations showing the highest accuracies were shifted mesially, no differences were found between the angles of -10 degrees and 20 degrees . The relationship between the roots and the furcation area was relevant to the range of angulations showing high detectabilities.

CONCLUSIONS

The angulations traditionally used for detecting proximal caries are also suitable for detecting furcation defects.